Acid Fixative

About Fixage

Acid fixer is a universal fixer that is best suited for fixing black-and-white film and sheet photographic materials. Unlike a neutral fixer, it offers superior fixing properties and better long-term stability. It is used for photographic films, photographic plates (including specialty types such as aerial photography, X-ray, and others), and photographic papers. It is recommended for use in all cases of processing black-and-white photographic materials. The only exception is when working with film that is significantly past its expiration date and has also been stored at elevated temperatures: in this case, it is better to use a neutral or tanning fixer to avoid damaging the weakened emulsion.

Character

Acid-based formula. A versatile fixative with better holding power and longer-lasting results than the neutral formula.

How to Prepare and Use

1. 1Dissolve the contents of the large package (250 g of crystalline sodium thiosulfate) in warm distilled or boiled water (25–40 °C) to a volume of 3/4 of the nominal amount.
2. 2Once the solution has completely dissolved and cleared, add the contents of the small packet (20 g of sodium metabisulfite) and stir until it is completely dissolved.
3. 3Let the solution settle and cool, then filter it.
4. 4Expose at an operating temperature of 20 °C—the standard exposure time indicated on the photographic material.
5. 51 liter of solution is sufficient for approximately 0.7 m² of photographic paper or 4–5 rolls of film; when processing the 4th roll, increase the fixing time by 15–25%, and for the 5th roll, by 20–35%.